Regurgitation is the usual complication of active infective endocarditis involving a cardiac valve. The development of valve stenosis entirely from infective endocarditis, of course, is extremely rare and worsening of previously existing valve stenosis by infective endocarditis rarely has been documented. In this report we describe one patient who appeared to have mitral stenosis (MS) purely on the basis of a large vegetation filling much of the previously normal mitral orifice and another patient in whom active infection clearly worsened preexisting MS.